This invention is directed to an environmentally sealed chip carrier housing for mounting to a printed circuit board (PCB) in which the chip therein contained becomes electrically interconnected to conductive elements on said PCB. Within such housing plural elastomeric compressive type connectors are provided as the interconnection means between said chip and said PCB.
A typical chip carrier is fabricated from a thin ceramic member having metallized circuit pads extending along a surface to the sides thereof. An electronic circuitry chip is mounted on the ceramic carrier, where fine wires are bonded between the circuitry and the pads of the ceramic carrier. Such chip carrier may be mounted within a housing, as known in the art and more fully described hereinafter.
To replace soldering of the chip carrier to the PCB, this invention contemplates the use of an elastomeric compressive type connector. Such a connector may be selected from a variety of designed connectors, as known in the art. By way of reference, a thin laminated elastomeric contact is taught in U.S. Ser. No. 352,223, assigned to the assignee herein. The invention thereof comprises an elongated body having plural laminations of electrically conductive metal sheet interspersed between layers of insulating material, where said laminations are oriented in a direction perpendicular to the axis of said body and that each metal sheet is electrically exposed on opposite sides thereof so as to be capable of electrically interconnecting a pair of substrates, disposed in parallel relationship, such as a chip carrier and PCB.
Another type of a compressible contact is taught in U.S. Pat. No. 4,203,203 to Gilissen et al. Briefly, such patent teaches an electrical connector formed from lamina of elastomeric material having conductive tracks on one surface by folding the lamina and bonding opposed lamina portions together. The conductive tracks extend around the fold between contact portions on opposite surfaces of the connector. The connector is essentially U-shaped, and in use rests under pressure between the aforementioned opposed substrates.
U.S. Pat. No. 3,985,413 to Evans teaches a different connector of the compressible type. Specifically, such patent is directed to a miniature electrical connector for forming connections between conductors on parallel spaced apart substrates. The connector comprises a generally cylindrical elastomeric body having a thin non-yielding flexible circuit wrapped therearound. The circuit has parallel spaced apart conductors on its surface so that when the connector is positioned between the two parallel substrates and compressed between the substrates, the corresponding conductors on the substrates will be electrically connected by the conductors on the flexible circuit.
Further examples of such connectors are found in U.S. Pat. Nos. 3,648,002; 3,795,037; 3,795,884; 3,861,135; 3,862,790; 3,885,173 and 4,003,621.
U.S. Pat. No. 4,376,560, assigned to the assignee herein, teaches a carrier chip holder which includes a molded insulative base carrying rows of discrete, metal resilient electrical terminals. A leadless chip carrier initially is supported on the terminals, with the pads of the carrier engaging the terminals. A lid is placed over the carrier and is rotatably advanced to press against the carrier, causing the carrier to deflect resiliently the terminals, and to seat against the base. The lid clamps the carrier against the base and is adjustable to accommodate a carrier which varies in height within specified tolerances.
A further example of a carrier chip holder, but one utilizing elastomeric conductors is disclosed in U.S. Pat. No. 4,843,313.
Neither of the latter patents, nor the prior patents discussed above, teach an environmentally sealed chip carrier housing in the manner of this invention; nor, are means disclosed by which to achieve a controlled pressure or torque on the chip carrier when disposed within said housing. Such features, along with others described hereinafter, shall become apparent in the specification which follows.